Search

• Flower fields can have similarly positive effects on bat activity as hedgerows. • AES can promote bats in agricultural landscapes and may provide suitable foraging habitats for bats in homogenous landscapes. • Critically endangered bat species were found flying above all our AES. Agri-environment schemes (AES) have become important tools for farmland biodiversity conservation, providing suitable habitats, resources, and connectivity within the agricultural landscapes. Bats are rarely studied in relation to AES effectiveness in contrast to birds, even though their presence and activity as biological control agents on insects, especially pest species, can be important for agricultural crops. While the role of hedgerows for bat occurrence and activity, as well as for their prey's diversity and abundance has been widely studied, the role of other AESs such as flower fields remains unclear. We monitored the activity of the main functional groups (edge, narrow and open space foragers) using ultrasound recorders, as well as potential prey abundances using light traps, across 35 study sites representing different AES in Central Germany from late July to September 2018. The sampled AES consisted of annual flower fields, mixed flower fields (with annual and biennial vegetation), perennial flower fields (sown every 5 years), hedgerows (surrounded by meadows and agricultural fields), and were compared to winter wheat (control) in a balanced design. Bat activity over hedgerows increased threefold for edge space foragers and sevenfold for narrow space foragers compared to wheat fields. Compared to wheat fields, narrow space forager activity increased fourfold over perennial flower fields, threefold over annual and twofold over mixed flower fields. This group's activity over hedgerows also increased almost threefold compared to mixed flower fields. However, the number of feeding buzzes and prey abundance did not differ significantly between AES. We detected foraging group-specific differences in bat activity between the studied AES. Thus, to promote bats in agricultural landscapes and to ensure their biological control services, it is important to establish more AES, such as hedgerows and flower fields, to increase their diversity and connectivity in intensively used agricultural landscapes. [ABSTRACT FROM AUTHOR]

• First high-resolution dietary analysis of the serotine bat (Eptesicus serotinus). • Detection of 254 taxa (at species or genus level) of 13 arthropod orders indicates a generalistic diet and the use of a broad variety of foraging habitats. • Equal use of Coleoptera, Diptera, and Lepidoptera, contradicting previous morphological dietary analyses that had shown beetles to be the most relevant prey. • Among the most frequently detected prey taxa were many pests of agriculture and forestry. • Seasonal variations in prey diversity and prey composition were mainly determined by the phenology of available prey. Bats play an important role as predators of insect populations but are threatened by a variety of factors, including the loss of foraging habitat and insect declines. Knowledge on trophic interactions, foraging strategies, and hunting areas is key to understanding the ecology of bat species, to assess their impact on ecosystems and to optimize conservation strategies. We investigated seasonal trends in the diet of two nursery colonies of the serotine bat, Eptesicus serotinus, from an intensively farmed agricultural landscape in Germany. Using DNA-metabarcoding of food remains in bat droppings collected from May to July 2018, we identified 254 taxa of 13 arthropod orders to species or genus level, including numerous pest species. Our results indicate an equal use of Coleoptera, Diptera, and Lepidoptera, contradicting previous morphological dietary analyses that had shown beetles to be the most frequent prey. The dietary composition was seasonally highly variable and mainly determined by prey phenology. Dietary richness significantly increased throughout the sampling period, reflecting increasing insect activity with progressing season. Our findings demonstrate that E. serotinus is a generalist forager, linking different habitat types through trophic interactions. [ABSTRACT FROM AUTHOR]

• A chaotic mechanism was introduced to enhance bat optimization algorithm. • An inertial weight was set for the velocity to improve the ability of global exploration. • Extensive benchmark problems were used to verify the proposed method. In this paper, a chaos-enhanced bat algorithm is proposed to tackle the global optimization problems. Bat algorithm is a relatively new stochastic optimizer inspired by the echolocation behavior of bats in nature. Due to its effectiveness, it has been applied to many fields such as engineering design, feature selection, and machine learning. However, the classical approach is often prone to falling into local optima. This paper proposes an enhanced bat algorithm to alleviate this problem observed in the original algorithm. The proposed method controls the steps of chaotic mapping by a threshold and synchronizes the velocity of agents using a velocity inertia weight. These mechanisms are designed to boost the stability and convergence speed of the bat algorithm, instantly. Eighteen well-established and the state-of-the-art meta-heuristic approaches are considered to validate the effectiveness of the developed algorithm. Experimental results reveal that the proposed chaos-enhanced bat algorithm is not only superior to the well-established algorithms such as the original method but also the latest improved approaches. Also, the proposed method is successfully applied to I-beam design problems, welded beam design, and pressure vessel design. The results show that chaos-enhanced bat algorithm can deal with unconstrained and constrained feature spaces, effectively. [ABSTRACT FROM AUTHOR]

The meta-heuristic algorithms have aroused great attention for controller optimization. However, most of them are inseparable from the explicit system models when addressing a constrained optimization problem (COP). In this paper, we propose a data-driven constrained bat algorithm via a gradient-based depth-first search (GDFS) strategy. In the proposed scheme, the GDFS strategy can predetermine a search space that satisfies some strict constraints (e.g., stability requirements) of the optimized system. Meanwhile, an improved boundary constraint handling method is proposed to limit the exploration process to the predetermined space. In this way, the proposed algorithm can solve the COP by utilizing experimental data from real scenes, thereby relieving the dependence on precisely modeling the complex system. Together with an ɛ -constraint-handling method, the bat algorithm is employed to seek the global optimum of the COP. The search performance is enhanced by the designed linear-varying elite layer-based local search and a social learning-based walk mechanism to dynamically balance exploration and exploitation. The convergence is ensured based on the criteria of the stochastic optimization algorithm. Experimental results on a servo drive system and benchmark test functions verify the effectiveness of the proposed algorithm. • Design a data-driven optimization method for the constrained controller tuning. • Design a gradient-based depth-first search strategy for strict constraints. • BA integrates a novel search mechanism to prevent premature convergence. • An improved boundary constraint handling scheme is proposed. [ABSTRACT FROM AUTHOR]

Automatically identifying bat species from their echolocation calls is a difficult but important task for monitoring bats and the ecosystem they live in. Major challenges in automatic bat call identification are high call variability, similarities between species, interfering calls and lack of annotated data. Many currently available models suffer from relatively poor performance on real-life data due to being trained on single call datasets and, moreover, are often too slow for real-time classification. Here, we propose a Transformer architecture for multi-label classification with potential applications in real-time classification scenarios. We train our model on synthetically generated multi-species recordings by merging multiple bats calls into a single recording with multiple simultaneous calls. Our approach achieves a single species accuracy of 88.92% (F1-score of 84.23%) and a multi species macro F1-score of 74.40% on our test set. In comparison to three other tools on the independent and publicly available dataset ChiroVox, our model achieves at least 25.82% better accuracy for single species classification and at least 6.9% better macro F1-score for multi species classification. • ConvNet-Transformer hybrid model enables sequence-based bat call classification, surpassing previous single call approaches. • Introducing synthesized mixed call sequences for multi-species identification, including overlapping calls. • Visualization of most informative calls within a sequence using attention maps. • Outperforming commercial tools and other methods with state-of-the-art results in bat call classification. [ABSTRACT FROM AUTHOR]

It is generally believed that the contributions of the UCP1-independent thermogenic pathways are secondary to UCP1-mediated thermogenesis in BAT. Now, Rahbani et al. demonstrate in vivo that adaptive thermogenesis in brown adipose tissue is regulated by UCP1 and CKB in parallel. [ABSTRACT FROM AUTHOR]

• A new method for evaluating roundness error based on improved bat algorithm was proposed. • Added chaos inertia weight and optimized adaptive pulse loudness and pulse emission rate. • Gaussian low-pass filter was used to preprocess the data. • Experimental results validated the stability, accuracy and timeliness of the improved bat algorithm. Roundness error is one of the core indicators for evaluating the geometric accuracy of round parts mechanical products, directly affecting product performance and service life. In the field of metrology, the accurate, rapid and standardized assessment of roundness error has always been a hot topic. This paper proposed a new method for evaluating roundness error based on improved bat algorithm. This method was based on the new geometric product specification for extraction, filtering and fitting. Based on the advantages of solving optimization problems using the bat algorithm, transformed the roundness error evaluation problem using the minimum zone method into a problem of using the bat algorithm to find the center of the minimum zone circle, then further solved for the roundness error value. Also, this algorithm effectively avoided falling into local optimal solutions by introducing chaotic inertia weights during the velocity update phase, it improved the accuracy and speed of the evaluation. Introduced adaptive parameters during the loudness and emission rate update phases to enhance the algorithm's global search capability, it enhanced the stability of the algorithm. The experimental results indicated, the efficiency of roundness error evaluation in the new method was significantly better than that of the genetic algorithm, the simplex algorithm and the emperor penguin algorithm. There was a significant improvement in evaluation accuracy and stability. The feasibility of this method in roundness error evaluation using the minimal zone method was validated. [ABSTRACT FROM AUTHOR]

• Forests constitute important refuge habitats for bats. • Relative activity of ten hawking bat species was analysed using acoustic surveys. • 713 point counts in 46 forests across mainland France were monitored over 6 years. • Ground deadwood cover and vegetation volume heterogeneity influenced bat activity. • Complex vegetation structures may enhance both ecosystem and bat conservation. Forests constitute one of the most important feeding and foraging habitats for bats. Because bat populations are declining, most likely due to habitat loss or fragmentation, it is imperative to understand the issues concerned with timber exploitation on bat conservation. We investigated the foraging activity of edge- and open-space foragers in relation to stand and vegetation structure, characteristics that are commonly affected by forestry. Acoustic surveys, culminating to 713 point count sites were undertaken covering 46 different forest massifs across mainland France over 6 years. We used generalized linear mixed models to analyse the activity of ten species: 6 edge-habitat and 4 open-habitat foragers. Pipistrellus pipistrellus was the most detected edge-habitat forager, while Nyctalus leisleri was the most recorded of the open-habitat foragers. Eptesicus serotinus and P. pipistrellus responded positively to heterogeneous vertical vegetation volume. In addition, P. kuhlii and P. nathusii responded negatively to tree basal area. Barbastella barbastellus , Hypsugo savii , and P. nathusii were associated with either ground deadwood and/or logging tracks and minor-traffic roads, confirming the importance of edge space. Finally, B. barbastellus, E. serotinus, and P. nathusii were positively linked to the presence of tree microhabitats. This study demonstrates that bat use in forests is complex and multifaceted. Maintaining ground deadwood and heterogeneity of vegetation, at the forest plot scale, should ensure the ecological functioning of exploited forest systems and the conservation of edge- and open-habitat foraging bats. [ABSTRACT FROM AUTHOR]

Highlights • Consultant and government foresters view endangered species management differently. • Foresters are unsure if management guidelines are effective for endangered species. • Foresters who intended to manage in line with the guidelines improved bat habitat. • Extension materials should provide evidence of how the guidelines aid bat conservation. Abstract Integration of conservation efforts that benefit endangered species in forest lands of the U.S. are highly dependent on the decisions made by professional foresters. Federal guidelines generally do not require private landowners to search for endangered species before conducting forest management activities. Because private lands make up 85% of Indiana's forests, recommendations by professional foresters can influence a large proportion of the management decisions made on Indiana bat (Myotis sodalis) habitat in the state. Thus, we wanted to determine what factors lead professional foresters in Indiana to adopt management strategies that benefit bat conservation. We conducted an online survey of Indiana consultant and state foresters to address two main objectives: (1) to assess forester understanding of guidelines for adequate bat habitat, and (2) to identify the factors that influence professional forester intention to manage forests to improve bat habitat quality. For a subset of survey respondents, we also determined whether forester intent to manage for Indiana bat habitat translated to on-the-ground behavior via an assessment of their stands marked for single-tree selection harvest. We found that most respondents knew some of the forest management guidelines for the Indiana bat, but few were familiar with all guidelines. Through structural equation modeling, we determined that intention to manage forests for the Indiana bat was influenced most by whether foresters believed following the guidelines would strongly influence the conservation of the species. We found a difference in the relative strength (path loading) of this factor between government and consultant foresters. We assessed the management decisions of a subsample of our survey respondents and found that respondent's decisions aligned with their intention to maintain or create Indiana bat habitat. We suggest two strategies can be employed to improve the habitat management occurring on private lands in Indiana: (1) increasing forester knowledge of federal guidelines and (2) providing evidence to foresters that these guidelines directly contribute to Indiana bat conservation. [ABSTRACT FROM AUTHOR]

Long-term mark-recapture studies are essential for bat conservation. Over the last decades, millions of bats across Europe and America have been marked with forearm rings for this purpose. Although it is considered a cost-effective method compared to Passive Integrated Transponders (PIT) tags, direct injuries from using forearm rings have been reported since their very first use. Yet, their impact on bats' welfare has not been systematically evaluated and remains a highly controversial issue among the scientific community and policymakers. Here we assess the impact of forearm rings and PIT tags on the health of different bat species. We reviewed 12 years of the existing recapture data of free-ranging bats from NE Spain and evaluated the impact of both marking tools in a captive colony of Carollia perspicillata , by assessing the development of skin lesions and levels of cortisol metabolites in guano (CG) after marking. We report that 55.1 % (435/790) of the recaptured free-ranging bats with forearm rings presented skin lesions. All banded C. perspicillata (n = 22, 100 %) developed skin lesions, whereas none of the PIT-tagged (n = 21) presented lesions. Levels of CG were significantly higher after marking with forearm rings only for one group. Banded C. perspicillata exhibited discomfort-associated behaviours due to forearm rings. Under the "precautionary principle", we recommend the ban of forearm rings for all bat species until species-specific studies under controlled conditions are performed and approved by a legally constituted ethics committee. Consideration of other long-term marking tools is mandatory to align with global bat conservation strategies. • Bat banding activities are performed worldwide on a large scale. • Band injuries are continually reported but it remains a controversial topic. • Banding activities assumptions introduce important biases in bat population studies. • A 12-year review and captive study highlight the impact of bands on bats' health. • Aligning with global conservation strategies, bat banding should be banned. [ABSTRACT FROM AUTHOR]